4gb gDDR3 vs 1gb gDDR5 & CrossFire APU questions..

[jamesgalb]

2 part questions...

(One)

Which r7-250 would be better with crossfire support for high-resolution gaming. A 4gb DDR3 setup, or 1gb DDR5 setup.

I ask because Im under the impression that in crossfire, memory works where 1+1=1 and 4+4=4... So the thinking is that if the intention is to crossfire for high-res 1080 gaming, that the 1GB DDR5 could become very limiting...

Thoughts?

(Two)

The ultimate goal is to find the optimal low-profile solution for an A10-7850k that is also AMD... the r7-250 happens to be the recommended crossfire-pairing AND the highest low-profile card AMD has atm, so it is a natural choice...

If crossfiring the r7-250 with the A10-7850k, would the DDR5 option be slowed down to the system/APUs DDR3 memory speeds?

If that is the case, I think the 4GB DDR3 option is clearly the better. Otherwise, I am getting mixed responses from question one...

 

[Techhog]

GDDR5 (remember to put the "G" or you'll be very confused in 10 years) is always better than DDR3. No exceptions. DDR3 is so slow that a having more will never make up for it. You're going to struggle with 1080p in recent games either way though, no matter what you go with. If you want 1080p, save up for an R7 260X or better.

 

[jamesgalb]

GDDR5 (remember to put the "G" or you'll be very confused in 10 years) is always better than DDR3. No exceptions. DDR3 is so slow that a having more will never make up for it. You're going to struggle with 1080p in recent games either way though, no matter what you go with. If you want 1080p, save up for an R7 260X or better.

R7-260X wont fit the low-profile case, and the case is a must... as the the AMD route, so no GFX750ti...

So you are saying that in 1080p gaming that 1gb gDDR5 > 4gb gDDR3 ? The 1GB wont cause the high resolutions to suffer more than the gDDR3? Some games recommend or require 4GB of vRAM, what about those games (Im thinking crossfired 250s have enough beef outside of memory)?

Also, main question would be if crossfiring with the APU disables the gDDR5 down the the APUs DDR3 speeds?

 

[Techhog]

R7-260X wont fit the low-profile case, and the case is a must... as the the AMD route, so no GFX750ti...

So you are saying that in 1080p gaming that 1gb gDDR5 > 4gb gDDR3 ? The 1GB wont cause the high resolutions to suffer more than the gDDR3?

Also, would crossfiring with the APU disable the gDDR5 down the the APUs DDR3 speeds?

No, the APU won't slow it down. Also, the 750 Ti is faster than using Dual Graphics with your APU and and an R7 250.

https://www.youtube.com/watch?v=lpGfA6g0-0Y

Watch that vid. The 750 Ti is nearly twice as fast.

 

[jamesgalb]

Will the APU use the system memory when the 1GB gDDR5 is exceeded?

I am cautious about going the 1gb gddr5 route because of how many games are recommending higher GBs or ram over any particular speed... Some games even require 2GB of vram, and others require it for certain resolutions...

Considering the focus is specifically 1080p gaming, wouldnt 1gb severely hurt me? Even with the extra speed, right?

 

[Techhog]

Will the APU use the system memory when the 1GB gDDR5 is exceeded?

I am cautious about going the 1gb gddr5 route because of how many games are recommending higher GBs or ram over any particular speed... Some games even require 2GB of vram, and others require it for certain resolutions...

Considering the focus is specifically 1080p gaming, wouldnt 1gb severely hurt me? Even with the extra speed, right?

You're not going to have a good experience using the R7 250 Dual Graphics either way. You'll have to play on low to get 1080p with it, and even then you'll struggle to get 30FPS in some games. You don't need to make that worse with slow memory. Here's another vid for you:

https://www.youtube.com/watch?v=6fa3fBFHseQ&list=UUjTCFFq605uuq4YN4VmhkBA

When using the R7 250, your RAM speed is no longer a bottleneck. If you run out, the game will stutter a bit before returning to the previous speed. If you use DDR3, you'll just get bad performance all of the time. If you'd prefer consistently bad performance over better performance with an occasional stutter, then you could go for the DDR3. Otherwise, it's just a bad choice that will leave you struggling to get 20FPS in some games. If a game is so demanding that it requires 2GB VRAM minimum, you're probably not going to get a playable experience even if you go with the 4GB DDR3

But, really, I strongly suggest saving up for the 750 Ti. It'll give you nearly double the performance you would get with Dual Graphics in some games for 50% more money. Unless you're extremely budget constrained, it's the best choice for your situation. Dual Graphics isn't as good as you think it would be, and it flat-out won't work in some games. If you absolutely can't justify saving up that much, get the GDDR5 R7 250.

 

[jamesgalb]

double post.

 

[Erenhardt]

I can't find it now, but there was a test that showed the DDR3 version of r7 250 working better in dual graphics with apu, then GDDR5.

Imho, the best card for dual graphics with kaveri is r7 240 2GB DDR3, because its almost like ad-in apu graphics.

 

[Techhog]

I can't find it now, but there was a test that showed the DDR3 version of r7 250 working better in dual graphics with apu, then GDDR5.

Imho, the best card for dual graphics with kaveri is r7 240 2GB DDR3, because its almost like ad-in apu graphics.

That's even more of a joke for what OP is asking though. Really, for OP's situation, the choices are save up for a 750 Ti, or deal with 720p. You can't have your cake and eat it too.

 

[frozentundra123456]

Too bad he didn't ask the question before purchasing the 7850k. A cheaper CPU with the difference put toward a stronger gpu would have been a much better solution.